Spectroscopic studies on the interaction between norfloxacin and FNC, 2′-deoxy-β-fluoro-4′-azidocytidine: analytical application for determination of FNC

Abstract

The interaction between norfloxacin (NFA) and FNC has been investigated by fluorescence and UV-vis absorption spectroscopy. It has been found that static quenching of fluorescence of NFA occurs in the presence of FNC. Hydrophobic interactions play an important role in stabilizing the complex. The binding constant (K), binding site number (n) and corresponding thermodynamic parameters have been determined according to the van't Hoff equation. This method is simple, selective and relatively free of interference from coexisting substances. Under optimal conditions, the relative fluorescence intensity is linearly proportional to the concentration of FNC between 1.29 and 36.20 μg mL⁻¹, with a detection limit of 0.2622 μg mL⁻¹. The recovery of the method is in the range of 97.8–99.9%.